Screw.



PATENTED JULY 3, 1906.

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SCREW.

APPLICATION FILED JULY 11. 1905.

By. s

UNITED STATES PATENT OFFICE.

CHARLES B. FARRINGTON, or BRooKLYN, NEWJYORK, ASSIGNOR OF'ONFF FOURTH TO STEPHEN T. LOCKWOOD; F BROOKLYN, NEW YORK.

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Specification of Letters Patent.

Application filed July 11, 1905- Serial No. 269,247.

' Patented July 3, 1906.

To all whom it may concern.-

Be it known that I, CHARLES B. FARRING TON, a citizen of the United States, residing in the borough ofBrooklyn, in the county of or other material in the usual manner, but

which cannot be Withdrawn without muti-' lation. I attain this. result by the device shown in the accompanying drawings, which Figure 1 is a view of the device, partly in section, with the false head inserted in the screw-body. Fig. 2 is a view of the same with the false head separated from the screwbody. Fig. 3 is an optional form of the device, artly in section, with the false head inserte in the screw-body. Fig. 4 is the optional form of the device shown in Fig. 3 with the false head separated from the screwbody.

Similar letters refer to similar parts through.- out the several views.

In a screw-body 0, provided with exterior screw-threads e e on its lower end section, I provide a longitudinal socket 11, extending om the top of the screw-body downwardly and provided with interior screw-threads f. The top of the screw-body a is smooth and not provided with any transverse slot for the screw-driver, as in the usual form of screw. I also provide a false head 0, the outer edge of which preferably conforms to the outer edge of the top of the screw-body d. Pro'ecting downwardly from'this false head 0 t ere is formed a projection c, screw-threaded to fit the screw-threads f in the. socket bin the screw-body. In use the projection c of false head 0 is inserted in the socket b in the screwbody a, when the screw-body a may be-turne'd and forced into the wood or other material in which the screw-body is to.be .inserted by means of a screw-driver or other suitable tool inserted in the transverse slot d in the false head in the usual manner. The screw-body having been thus inserted it will be found that when it is attempted to withdraw the screw in the usual manner by a reverse turn the false head 0 will be withdrawn and the screw-body a will remain and will not be moved by any 5 5 reverse turn of the false head a. y

- An optional form of my device adapted for a flat-head screw is' shown in Figs. 3 and 4. The false head 7c is provided with a transverse slot 1 and the screw-threaded projection m to fit into the socket 'i in the screw-body g, provided with exterior screw-thread h, and is o erated in the same manner as the form s own in Figs. 1 and 2, above described. Where the screw is to be inserted in a hard substance, the false head may be strengthened by providing a beveled section n at the oint where the projection m is joined to the alse head it, and the upper end of the socket i in the screw-body a is 1n such case flared at '5 to receive the enlarged section a. of the projection m of the false head is.

Having thus described my invention, what I claim is y A screw having a body formed with an en-, 7 5 larged head and with exterior screw-threads, said body having an interiorly-screw-threaded socket which is surrounded by an unbroken wall on the outer face of said head, and means for inserting said screw into the desired position consisting of a head slotted on its outer face and provided with a screwthreaded projection, the relative construe-- tion being such that 'the under face of the lastnamed head may engage the outer face of the first-named head.

In testimony whereof I affix my signature in presence of two witnesses.

CHARLES E. FARRINGTON. Witnesses:

J USTIN S. HOLLAN GEORGE M. Fotmns. 

